Merely this, my Lord. The memorandum of understanding, like the DGNs 8, 10 and 17, fix the practice that is going to be followed by the respect governments in order to maintain dialogue, in order to maintain communication, and in order to maintain coherence in circumstances where there are two sources of legislation for particular parts of the United Kingdom. But more particularly, and more narrowly, the Sewel convention is an expression of what Parliament will do. It is an expression of its self-denying ordinance.
One has to bear in mind it follows section 28(7), which reiterates the absolute sovereignty of the Westminster Parliament. It is then followed by the words "but it is recognised", and I simply pose rhetorically the question, recognised by whom? It is recognised by the sovereign Parliament.
That is not consistent with a justiciable matter.
But perhaps there is a more significant point to make, and it was one brought out by my Lord, Lord Mance, which is there is on the face of it no possible remedy if the sovereign Parliament does not adhere to the Sewel convention, and it might appear to be an unduly narrow and civilian approach to matters, but if there a right there is a remedy. If there is no remedy, is there a right?
In my respectful submission, even as you begin to pursue the idea of a remedy, you come up against Article 9 of the Bill of Rights and against the Claim of Right, and one cannot go past that, it is perfectly clear. So in light of this, while Article 50 may refer to constitutional requirements, it is quite impossible to see how the Sewel convention can constitute one of those constitutional requirements.
At one point my learned friend the Lord Advocate said: well, I will take any proposed bill in its narrowest terms, and I will then test matters by reference to that.
Well, let us suppose that there is a bill to authorise the giving of notice under Article 50 to the EU. That is not on any view a bill with regard to devolved matters. So applying the Lord Advocate's own test, it is really quite impossible to see how the Sewel convention can be elevated into a constitutional requirement for the purposes of Article 50.